The primary goals of this research are to gain a detailed understanding of the structure and function of two membrane transport enzymes, the Ca2 ion-ATPase and the (Na ion plus K ion)-ATPase, and to characterize the mechanism of ion transport itself. These enzymes, which play important roles in many metabolic processes, including muscle contraction and excitability in brain and nerve tissue, will be studied using a variety of nuclear magnetic resonance, electron spin resonance and kinetic studies. The active sites of these enzymes will be characterized with respect to substrate and metal ion binding, and paramagnetic probes such as Mn2 ion, Gd3 ion will be used as probes to determine the conformations and locations of ion substrate binding sites on the enzyme. The purified enzymes will be reconstituted into lipid vesicles using natural and synthetic phospholipids and these reconstituted transport systems will be studied using NMR and spin labelling methods to characterize the orientation of the systems in the membrane and to attempt to resolve the channel vs. carrier controversy for these systems and determine precisely how the metabolic energy of ATP is converted to the mechanical energy of ion transport.